This application claims the benefit of the Korean Application Nos. P2001-24857, 24931, 24858, and 24860, all of which are filed on May 8, 2001, and hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a method for defrosting a refrigerator with two evaporators, in which defrosting periods of a freezing chamber evaporator and a refrigerating chamber evaporator preset at a controlling part are changed for defrosting the two evaporators on the same time when defrosting operation time points of the two evaporators come close.
2. Background of the Related Art
The refrigerator stores food in a frozen state, or food, such as vegetables and kimchi, in a low temperature state. A related art refrigerator will be explained with reference to FIG. 1. FIG. 1 illustrates a related art refrigerator with two evaporators, schematically.
Referring to FIG. 1, the refrigerator is provided with a freezing chamber 6, and a first storage chamber 7 and a second storage chamber 8. There are a freezing chamber evaporator 6a at one side of the freezing chamber 6, and a storage chamber evaporator 7a at one side of the storage chambers 7 and 8. There are a freezing chamber fan 6b and a defrosting heater 6c adjacent to the freezing chamber evaporator 6a, and there are a storage chamber fan 7b and a defrosting heater 7c adjacent to the storage chamber evaporator 7a. There are a compressor 1, a condenser 2, a three way valve 3, and respective expansion devices 4 and 5 on outside of the freezing chamber 6b and the storage chamber 7 and 8.
There are temperature sensors (not shown) fitted to the freezing chamber 6 and the storage chambers 7 and 8, for sensing and providing temperatures of the freezing chamber 6 and the storage chambers 7 and 8 to a controlling part (not shown).
In order to maintain temperatures of the freezing chamber 6 and the storage chambers 7 and 8, there are upper limits and lower limits of the temperatures of the freezing chamber 6 and the storage chambers 7 and 8 set at the controlling part. A range between the upper temperature limit and the lower temperature limit is called as a preset temperature range.
Moreover, respective storage chambers 7 and 8 are operative in a vegetable or fruit storage mode, a kimchi storage mode, or a kimchi fermenting mode depending on press of buttons by the user. The temperature ranges of the storage chambers 7 and 8 are required to be set to differ with the storage mode, the kimchi storage mode, or the fermenting mode. For an example, the storage chambers 7 and 8 are operative at a temperature range of approx. xe2x88x921xcx9c3xc2x0 C. in the storage mode, approx. 19xcx9c21xc2x0 C. in the fermenting mode.
The operation of the foregoing refrigerator with two evaporators will be explained.
High temperature high pressure refrigerant compressed at the compressor 1 is provided to a condenser 2, and the refrigerant condensed at the condenser 2 is provided to the three way valve 3. If the temperatures of the freezing chamber 6 and the storage chambers 7 and 8 are not within the temperature ranges preset at the controlling part, the three way valve is opened in a R/F cycle mode, when the refrigerator conducts the R/F cycle in which the refrigerant, passed through the compressor 1 and the condenser 2, flows through the three way valve 3, the second expansion device 5, the storage chamber evaporator 7a, and the freezing chamber evaporator 6a in succession.
If the temperatures of the storage chambers 7 and 8 are within the temperature ranges preset at the controlling part, but the temperature of the freezing chamber 6 is not within the temperature range preset at the controlling part, the three way valve 3 is opened in an F cycle mode, when the refrigerant, passed through the compressor 1 and the condenser 2, flows through the three way valve 3, the first expansion device 4, and the freezing chamber evaporator 6a in succession.
Of course, if all the temperatures of the freezing chamber 6 and the storage chambers 7 and 8 are within the temperature ranges preset at the controlling part, operation of the compressor 1 is stopped, to stop flow of the refrigerant.
There is frost formed on the evaporators 6a and 7a as the refrigerator is thus operative for a prolonged time period in the R/F cycle or in the F cycle. Since the frost drops thermal efficiencies of the evaporators, defrosting operation is conducted for removing the frost at the evaporators.
For this defrosting operation, there are defrosting periods for respective evaporators 6a and 7a preset at the controlling part for carrying out the defrosting operation periodically. That is, the controlling part accumulates an operation time period of the compressor 1, to carry out the defrosting operation of the evaporators independently, once the operation time period is accumulated to a preset time period. For an example, the defrosting operation of the storage chamber evaporator 7a is carried out whenever the accumulated time period of the compressor 1 is 10 hours, and the defrosting operation of the freezing chamber evaporator 6a is carried out whenever the accumulated time period of the compressor 1 is 22 hours.
When the accumulated time period of the compressor 1 reaches to the defrosting period preset at the controlling part, the refrigerating cycle is stopped at the time point of defrosting operation, and the defrosting heaters 6c and 7c provided adjacent to respective evaporators are put into operation, for defrosting the frost on the evaporators. Upon a pause time period is passed after the defrosting operation of the evaporators are finished, the compressor is put into operation, to operate the refrigerator in the F cycle or in the R/F cycle.
In the meantime, for defrosting the freezing chamber evaporator 6a, it is required that the defrosting is carried out only when the refrigerating cycle is finished to stop the compressor 1 regardless of the operation of the refrigerator being in the F cycle or R/F cycle. This is because the refrigerant flows into the freezing chamber evaporator 6a regardless of the operation of the refrigerator being in the F cycle or R/F cycle.
In comparison to this, for defrosting the storage chamber evaporator 7a, though defrosting of the storage chamber evaporator can be carried out without stopping the compressor 1 if the refrigerator is operative in the F cycle, it is required that the defrosting of the storage chamber evaporator 7a is carried out only when the refrigerator finishes the R/F cycle to stop the compressor if the refrigerator is operative in the R/F cycle.
However, because defrosting of the freezing chamber evaporator 6a and the storage chamber evaporator 7a is independent, which are operative according to the accumulated time period of the compressor 1, there has been a problem in that, even if one of the evaporators is defrosted not so long ago, the other evaporator comes into a defrosting period.
For an example, if the storage chamber evaporator 7a reaches to a defrosting period during the refrigerator is operative in the R/F cycle, the defrosting of the storage chamber evaporator is carried out when the compressor 1 is stopped as the R/F cycle is finished. Then, if the freezing chamber evaporator 6a reaches to the defrosting time period within a short time period from the defrosting of the storage chamber evaporator, it is required that the defrosting is carried out when the compressor 1 is stopped as the R/F cycle is finished.
Eventually, the frequent stop and starting of the compressor, not only causes a pressure loss of the compressor, but also increases power consumption of the refrigerator.
Moreover, if the defrosting to the freezing chamber evaporator 6a is carried out in a state temperatures of the storage chambers and the freezing chamber are close the upper temperature limits of the preset temperature ranges, the temperatures of the storage chambers 7 and 8 and the freezing chamber 6 rise above the upper temperature limits of the preset temperature ranges from a time point the defrosting of the freezing chamber evaporator starts to a time point the defrosting of the freezing chamber evaporator starts again, that cause to required much power for dropping the temperatures of the freezing chamber 6 and the storage chambers 7 and 8 down to the preset temperature ranges.
Moreover, the operation of the freezing chamber and the storage chambers outside of the preset temperature ranges result in failure of maintaining the temperatures of the freezing chamber and the storage chambers with fixed ranges.
In view of current trend of refrigerator technologies, since it appears that maintaining inherent taste of food, such as kimchi, and reducing power consumption of the refrigerator by maintaining temperatures of the freezing chamber and the storage chambers are key points of technical capability, measures for those are required.
Accordingly, the present invention is directed to a method for defrosting a refrigerator with two evaporators that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a method for defrosting a refrigerator with two evaporators for improving power consumption of the refrigerator and prevent a pressure loss of a compressor.
Another object of the present invention is to provide a method for defrosting a refrigerator with two evaporators, for stable maintenance of temperatures of a freezing chamber and storage chambers within preset ranges.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, in defrosting a refrigerator with two evaporators, the present invention suggests determining a defrosting time point of the other evaporator when one of the evaporators reaches to a defrosting time point for defrosting the two evaporators on the same time if the defrosting time points of the two evaporators are close, or defrosting the two evaporators separately if not.
Moreover, in the present invention, when the freezing chamber evaporator is defrosted, it is designed that the defrosting is carried out after temperatures of the freezing chamber and the storage chambers are lowered to lower limits in advance, and when all the storage chambers are operative in kimchi fermenting modes, it is designed that no defrosting of the storage chamber evaporator is made even if the storage chamber evaporator reaches to a defrosting time period, for preventing unnecessary defrosting.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.